Yes, as long as you understand their purpose. They exist as a form of class signalling. [0] Many of the older forms of nepotism/cronyism have been made illegal. Racial and IQ discrimination are also illegal. Therefore, business schools and law schools fill the gap. They exist to tell an employer that the applicant is either a member of their class or an ally.
Suppose you take a veteran engineer heading into management, and send him/her to get an MBA. Will they come back no better for it?
You won't find engineers saying that medical degrees are just BS.
Fact is, business degrees are thin on content. I know this because I studied engineering and went to a business school. Now of course any degree has some kind of content, but business content just has very little that would pass for being academic content. The core stuff like Porter's Five Forces and Taylorism is no different than what you'd "know" if you read some of those airport magazines now and again.
Imagine an engineering class where you just watched a Discovery show about how the Channel Tunnel was made. Yes, it's content, but nobody should be hired to build tunnels based on having seen that video of the French guy shaking hands with the British guy.
But that is how we hire executives. A guy who knows some things about the history of some industry, and can talk about it confidently.
> Suppose you take a veteran engineer heading into management, and send him/her to get an MBA. Will they come back no better for it?
They'll know something about the culture of management, which will be useful for duping someone into promoting him. Well actually I rather like the idea of having technically trained managers, so I'd cheer that on. But not because you'll know how to manage from studying management.
Business schools can serve a very productive education service when students take the finance/accounting tracks if they don't have those backgrounds. This allows people without those backgrounds to either transition into new careers or get the underlying knowledge they need to take on new responsibilities/roles in their existing careers.
A lot of work in both finance and accounting are 'complex' so daily practice require detailed knowledge. Even if they may not be 'sophisticated', (e.g. PhD level mathematics). Some areas, like derivatives, are both complex and sophisticated.
Sources: 1. My Mom got an MBA to change fields and then used her learned knowledge in finance+accounting constantly working for a state municipal agency. 2. Our CEO got an MBA to learn the knowledge he needed to move forward in his career/transition into different roles.
I agree with the other responses to you question that in some areas of the US (e.g. Silicon Valley, East Coast) a 'name brand' MBAs may be used as a signaling requirement for certain jobs or to advance in a career - more so than for eduction. This gets more silly when a personal already has the necessary skills! And part of the value these schools supply to their graduates a network of similarly interested business contacts.
So would the veteran engineer moving into management be helped... perhaps/but probably not. But can a person looking to change fields or areas benefit hugely by doing an MBA? Yes. Absolutely.
As indicated in your link, IQ tests and diplomas are treated the same way by Griggs: they are okay when they are a reasonable measure of job performance and not okay when they're not.